Dry control apparatus and circuitry for a dry cleaner



1966 J. T. WILLIAMS ETAL 3,234,660

DRY CONTROL APPARATUS AND CIRCUITRY FOR A DRY CLEANER Filed Aug. 8, 19623 Sheets-Sheet 1 INYENTORS dam e s 7'. l'Vl/h'dm s dames L M-Uwm e//TORNEYS Feb. 15, 1966 J. T. WILLIAMS ETAL 3,234,660

DRY CONTROL APPARATUS ANDFCIRCUITRY FOR A DRY CLEANER Filed Aug.. 8,1962 I 3 Sheets-Sheet 2 INVENTORS MIA/07' E S w m X M e mm Odm dames 7.iVM/fams dames A. M-Co/me// mmk mt M A ORNEYS s L m m m E E w T if A? r?5,4 3

FUNCTION N2 BY-PAS-S I06 T/MEE M736.

ma 115/4 TEE m9 BLOWER CO/VO. PUMP Feb. 15, 1966 J. T. WILLIAMS ETAL3,234,660

DRY CONTROL APPARATUS AND CIRCUITRY FOR A DRY CLEANER Filed Aug. 8, 19623 Sheets-Sheet 5 27 Y X I L J Fig.5 55

I 7 75 7.; gflgo OIIMHV M p mm INVENTORS dame: T 144/001: c/am esLM-Carme United States Patent 3,234,660 DRY CONTROL APPARATUS ANDCIRCUITRY FOR A DRY CLEANER James T. Williams, St. Joseph, and James L.McConnell, Stevensville, Mich., assignors to Whirlpool Corporation, St.Joseph, Mich, a corporation of Delaware Filed Aug. 8, 1962, Ser. No.215,565 Claims. (Cl. 34-45) The present invention relates to an improvedapparatus for drying cleaning, and more specifically, to improvements inthe field of coin-operated automatic dry cleaning machines.

In a typical coin-operated dry cleaning assembly, the articles to becleaned are tumbled with a liquid dry cleaning solvent such asperchlorethylene in a washing zone, excess solvent is drained, and thena current of hot air is passed through the articles to vent off solvent.In such systems, solvent recovery is effected by condensing the solvent,filtering and returning the solvent to the Washing zone.

In a typical automatic dry cleaning apparatus, the duration of the washcycle, the rinse cycle, and the drying cycle are under the control of amaster timer mechanism. Such a timer, however, cannot to our knowledgebe conveniently modified to take into account variations in the size ofthe load being cleaned, Thus, it is entirely possible with a small loadto have an excessively long drying cycle, with a resultant waste of heatenergy and possible adverse effect on the articles themselves.Conversely, with a larger than normal load, the drying cycle may beinsufiicient to vent the solvent completely with the result that at theconclusion of the normal timed drying cycle, the clothes may still bedamp or may have an objectionable odor of solvent. The retention ofsolvent in underdried fabrics processed in a publicly operated drycleaning machine is objectionable from a cost standpoint because of theloss of such solvent and also because the retained solvent in suchunderdried fabrics, such as rugs and other bulky items, may be offensiveor create certain hazards.

It is accordingly an object of the present invention to provide animproved dry cleaning apparatus in which the drying cycle isautomatically varied in response to variations in the load beingcleaned.

Another object of the present invention is to provide an improvedcontrol system for automatically deactivating the timer mechanismemployed in automatic dry cleaning assemblies and making the dryinginterval dependent upon the nature of the clothes load and operation ofthe vapor condenser incorporated in the dry cleaner.

Still another object of the invention is to provide a mechanism forsensing the rate of flow issuing from the condenser of a dry cleaningapparatus and using this sensing mechanism to control the duration ofthe drying cycle.

A further object of the invention is to provide a failsafe means for theimproved control system.

A still further object of the invention is to provide circuit means forsensing a malfunction in the improved control system during the dryingcycle and for automatically completing the dry cycle in the event of amalfunction.

An additional object of the invention is to provide an improved drycontrol system employing first sequential control means for carrying outa variable time dry cycle and a second sequential control meansinterconnected by circuitry means to the first sequential control meansfor overriding the first sequential control means in the case of amalfunction of the dry control system.

Another object of the invention is to provide a dry control system for adry cleaner which provides for con- ICC tinuous operation of the solventventing system in the event of a malfunction in the automatic control,thereby substantially eliminating the possibility of recoveringsolvent-laden clothes in the event of such malfunction.

Still another object of the invention is to provide control circuitryfor a drier assembly which compensates by means of overriding circuitelements to eliminate solvent from the articles whenever the load isheavier than normal, or upon the existence of any malfunction whichmight tend to terminate venting of the solvent prematurely.

Another object is to provide an improved dry cleaning method.

Other objects and features of the present invention will be apparent tothose skilled in the art from the following description of the attachedsheets of drawings which illustrate a preferred embodiment.

In the drawings:

FIGURE 1 is a somewhat schematic view of the complete dry cleaningassembly;

' FIGURE 2 is a timing chart illustrating the intervals involved insequence during the operation of the dry cleaning assembly;

FIGURE 3 is a somewhat schematic wiring diagram of the dry controlapparatus of the dry cleaning machine;

FIGURE 4 is a plan view of the water separator and float switch assemblyemployed in the dry control apparatus; and

FIGURE 5 is a cross-sectional view taken substantially along the line VVof FIGURE 4.

As shown on the drawings:

In FIGURE 1, reference numeral 10 diagrammatically indicates generally acasing for receiving the articles to be cleaned and containing arotatable, perforate drum 11 mounted for rotation on a shaft 12 drivenby the motor drive means illustratively shown by numeral -13. An accessdoor 14 is provided to permit introduction of the articles to be cleanedinto the interior of the drum 11. The housing 10 is provided with aconically shaped bottom portion 16 Which acts as a sump to collectliquid dry cleaning solvent and discharges it through a line 17connected thereto. Dry cleaning solvent is fed to the housing 10 bymeans of a line 18 so that it is injected onto the contents of the drum11 during the wash cycle. A heater 19 is also located within the housing10 and serves to heat air entering the drum 11 for drying purposesduring the drying cycle.

Solvent vapors are vented from the housing 10 by means of a conduit 21located at the rear of the housing 10 and feeding a condenser assemblygenerally indicated at 22 in the drawings. Solvent laden air vented fromthe housing 10 passes through a lint filter 20 and a condenser 23,normally of the tube and fin type, by the action of a blower generallyindicated at numeral 24 in the drawings. The air is then directedthrough a conduit 26 past the heater 19 back into the housing 10, whilethe condensed solvent is withdrawn through a line 27 for purposes whichwill hereinafter be explained more fully.

The unit shown in FIGURE 1 includes a solvent reservoir 28 containing abody of solvent generally indicated at 29. A refrigeration coil 31 isimmersed in the solvent body 29 and is cooled by means of arefrigeration unit indicated at 32 in the drawings. Coil 31 andrefrigeration unit 32 are coupled as one assembly. This assembly is inan opening in the top 28a of reservoir 28. A submerged pump 33 driven bya motor 34 delivers the cooled solvent from the reservoir 28 through aconduit 36 to a filter 37 Where impurities are removed from the solventbefore its return to the system. The discharge from the filter in adischarge line 38 can be passed directly into the inlet line 18 feedingthe housing 10 by opening a valve 39 connecting the two lines. A portionof the discharge of the filter 37 can alsobe directed into a conduit 41controlled by a valve 42 for introduction into the cooling coilscontained in the condenser 23. The discharge from the cooling coils istaken through a conduit 43 and returned to the solvent reservoir 28.

The present invention is particularly concerned with a sensing devicewhich is actuated bythe operationof the condenser mechanism to therebydetermine the length of the drying cycle. To that end, the liquid.condensate recovered from the :condenser 22 and flowing through line 27:passes througha waterseparator 47 and then through a drying controlmechanism generally indicated by numeral 481m FIGURE 11. .These twoassemblies are best illustrated in F'IGU'RES '4..-an'd of the drawings.As seeninthose figures, the condensate in the line 27 is passed to acylindrical water separator 47 having a threaded bottom portionclosed bymeans of a cap 51;and sealing gasketi52. The cap 51 may 'be removed toclean the water separator 47. A pair of substantially fiat surfaceddependingrbaffiesa53-and 54 of different lengths extend chordallyacross'the cylindrical housing of :the separator 47. .Thedischarge fromthe condenser appearing in line 27 will consist of a mixture ofcondensed water=and condensed solvent. 'As the condensate builds upintheseparator 47, the bafi les53 and 54 separate the water from thesolvent. Since the water is lighter than the solvent, it flows to thetopand is trapped in a chamber56 between theba'flles 53 and 54. Duringmaximum discharge from the condenser, the

water level will be at a line indicated. at '57 in the drawings, andexcess water can be continuously withdrawn by an overflow conduit 58:provided for that purpose. An air vent 59 is also provided'in'the-water separator 47 to prevent excessive pressnre'from buildingup. Itwill be noted from an inspection ofFIGURES 4 and 5 that the body portionof water separator '47 and-the body portion of the condensate collector48 are interconnected by a vertical mounting web50 permitting uprightinstallation and that'the internal chambers of these body portions areslightly tapered for easier molding as well as to accommodate freemovement of the some what frusto conical fioatf69. i i i The solventflows under thebafiie '53into a conduit 61 connecting with thecondensate sensing 'or dry control mechanism 48. The 'latter'includesacasing 62 having a threaded end portion closed by means of a cap '63 inthreaded engagementwith thecasing 62. "The bottom of the cap63is't'ormed with a metering orifice 64, and the cap pressesawsealingr-gasket-66 against a ceramic filtering element 67 located atthe -base of the casing "62. 'Condensate' generated by condenser '23passes from conduit '61 into a chamber-'68 within the dry controlmechanism 48 and serves to operate a float 69 contained therein. Whentherate of flow o f condensate entering the chamber'6'8 is greater than therate at which the condensate'is leaving through the metering orifice 64,the floatr69 will rise in the chamber68. The fioat'69 is provided with aswitch actuating projection 71 which is aligned with an actuating arrri72 of a single-pole, double-throw switch '73 having a first lowerposition and a second upper position." =As'long asthere is sufiicientexcess fiow 'wi thin the chamber 68, the switch 73 willbeoperated' toits second upper position and'any additional excess condensateisreturne'd to the reservoir 28 by means of conduit76. When there isinsufiicient'flow within the chamber 68,-the fl0at will fall and theswitch 73 wi'llreturn to its'first or lower position. The discharge ofthe metering orifice 64 isalso returned to thereservoir 28 by means ofabranch conduit 77.

The electricalcircuitfor controlling operations of the dry cleaningassembly is best illustrated in FIGURES 2 and'3 of the drawings.Referring'first to FIGURE 3, numerals 81 and'82 have been applied 'tothe two sides of the line which supplies electrical .power to the seriesof earns 88 through 94, inclusive.

unit. A door switch 83 is included in the line 81 so that the machinecircuitry cannot be energized without the door being closed. The balanceof the machine circuitry, apart from a portion of the timing mechanism,has been broadly identified atz-84 since these circuits form no part ofthe instant invention.

The principal timing control is afforded by a main timer motor86 havinga shaft 87 on which are mounted sequentially energized switch contactscontrolled by a A manual reset knob 96 isprovided in 'conjunction withthe main timer motor 86 for resetting the operations of the timer motorto its zero position 1as.'desired.

.An auxiliary timer motor-.9 8 is also provided, t g with its manualreset means 99. The auxiliary timer motor 98 has a shaft 101 whichcarries a pair of cams 102 and '103 to operate switches 114 and 116 intimed sequence, as will be explained in a succeeding portion ofthisspecification.

FIGURE 52 illustrates the timing schedule arrangement provided by thevarious cams operating from the main timer motor 86 and the'auxiliarytimer motor '98. A total of 60timer intervals, each one-half minute induration, is shown for convenience though it should be appreciated.atthe outset-hereof that thetotal elapsed time of this illustrativecycle may exceed thirty minutes.

.At the outsetiof the-timing interval, it will beseen fromFIGURE '2,which is read from left to right, that Switches106 and107,associate'd'with cams-89 and 90, respectively, are closed, therebyapplying energizing voltaget-hrough parallel circuits to the switches1-06 and 1017 across the main timer motor 86. At-the beginning ofthetwenty-sixth timer interval,the heating element 19 and the blower F24are energized, effectively initiating the drying period,-by timingcams'92 and 93'through their associated switches 108 and 109 to preheator warm up the dry cleaning unit during awportion of the extractionperiod. At the beginning of the twentyeighth timer interval, solvent isconveyed from the reservoir..2'8 byenergizing pump33th-rough' theoperation of cam 941and its associated switch 111, therebydeliveringsolvent through the conduit '36 into thefilter'37,'to conduit 38,pastvalve :42 and .into the condenser :23 to precool the condenser. Atthe end of twenty-ninthv timer interval, the extraction period .ends,and the drying period: continues.

At the beginning of the pthirty-fourth timerinterval, cam 91 serves toclose thejfirst byrpass switch .112 and cam-: is timed tosopen'thesecondbypass switch 107. At the :beginning of the thirty-fifth timer interval,cam 89 operates to. open switch :106. The movement .of switches 112,107and106,aat.this time, provides .a checking interval to detect'whethertor'not float 69 is in itsupper position. Normallyin-dryingregular fabrics there should be sufiicient amounts of. condensate atthispoint of the cycle in thecharnber168, to raise. the float 69- to where.it operates the single-pole, double-throw switch 73 into its upperposition .as iseenin'FIGURE 3. Line voltage. is thereby supplied to thetimer motor 86 through the switch 73-and the. now closed first'by passswitch 112, connected in parallel shuntingrelationship around switch'106to continue operation of the timer motor =86. Theswitch 106 remains openfor onetimer interval, and at the end of the thirty-fifthtimer-interval, the cam 89 operates to reclose switch 106.

Also, at the beginning of the thirty-fifth timer interval, the cam88operates to close its associated auxiliary timer motor'switch 113and'thereby apply line voltage across the auxiliary timer motor 98. 1

Switch 73 is responsive to condensate flow which generally decreasesasthe over-all condition of dryness of the articles in:drum '11 increases.In a broader form of this invention switch '73 could also be in the formof a thermal responsive element sensitive to the temperature of thefabrics or temperatures of exhaust air from drum 11 and movable from itsupper to its lower position during the drying cycle since thetemperature of fabrics or exhaust air increases upon attainment of theover-all condition of dryness.

At the beginning of the thirty-seventh timer interval, the cam 91operates to open the first by pass switch 112 and the cam 90 operates toclose the second by pass switch 107. This switching arrangement providesa second checking interval to detect whether the float 69 is in itslower position when cam 89 operates to open main timer motor switch 106at the end of the fifty-fifth timer interval.

At the beginning of the thirty-ninth timer interval, the auxiliary timermotor 98 moves the cam 102 to a position in which it closes itsauxiliary motor by pass switch 114 to provide a by pass or shunt circuitaround auxiliary timer motor switch 113. This allows continuedenergization of auxiliary timer motor 98 after switch 113 issubsequently opened by cam 88 at the beginning of the fortyflfth timerinterval.

At the beginning of the fifty-fifth interval, the cam 89 operates toopen the main timer motor switch 106. It is at this time that thevariation of load size affects the operation of the main timer mechanism86. With a reasonably light load or moderate load, the articles will besufficiently dry at this time, and insufiicient condensate will flowinto chamber 68 to keep the float 69 in the upper position. The floatwill fall and the switch '73 will have returned to its first or lowerposition. Line voltage will thereupon be continued to the timer motor 86through the lower contact of switch 73 (which is now in the positionshown in FIGURE 3) and through the second by pass switch 107 whichremains closed. At the beginning of the fifty-sixth timer interval, thecam 89 operates to close the main timer motor switch 106 again and thetimer 86 continues to be energized. It is at this time that the heatedportion of the dry period ends and the deodorize period begins. At thesame time, the heater 19 is de-energized as is the pump 33 whichrecirculates the condensate. Blower 24, however, remains energizedthrough closed switch 109 to vent to the atmosphere, by means not shown,the last traces of solvent vapor from the articles during thedeodon'zing period. The machine cycle is then completed at the end ofthe sixtieth timer interval at which time cam 90 operates to open thesecond by pass switch 107, cam 89 operates to open the main motor switch106 and the blower 24 is de-energized by cam 93 opening blower switch109.

However, if the articles are still insufficiently dry at the beginningof the fifty-fifth timer interval or if a malfunction occurs such as thefloat 69 or switch 73 sticking in their upper positions or the orifice64 in the control chamber 68 plugging with foreign matter, the circuitoperates as follows:

In the case of insufiiciently dry articles, the main timer motor 86 willremain de-energized because the rate of flow of condensate is suflicientto keep float '69 in its upper position which in turn keeps switch 73 inits second or upper position. Therefore, since the first by pass switch112 is open, the operation of the main timer motor 86 will beinterrupted and the drying operation will be extended until float 69falls and thereby re-applies line voltage through the lower contact ofswitch 73 and the second by pass switch 107 to the main timer motor 86so that the machine cycle is thereafter completed in exactly the sameway as it would have been for lighter loads.

As previously mentioned, the auxiliary timer motor 98 is initiallyenergized at the beginning of the thirty-fifth timer interval. Theauxiliary timer motor 98 is preset to operate for thirty minutes orsixty intervals of the timer chart in FIGURE 2. If at the end of thethirty-minute period of the auxiliary timer motor operation the float 69is still in the upper position where it holds switch 73 in its second orupper position, cam 103 will be operated by the auxiliary timer motor 98to close its associated switch 116 which closes after thirty minutes ofactual timed operation of auxiliary timer motor 98 have elapsed (andtherefore not shown in FIGURE 2). However, since the first by passswitch 112 is open, a circuit is not completed to the main timer motor86, through switches 116 and 112 and the machine continues to dry untilthe switch 73 falls to its lower position thereby energizing timer motor86 through the second by pass switch 107 and the lower contact of floatswitch 73. This action provides an infinite drying interval so thathard-to-dry articles such as sleeping bags, rugs, blankets and otherbulky articles, can be completely dried to a desired dryness before themachine will terminate this drying operation. After the main timer motor86 has been energized, the drying operation is normally effectivelyterminated by timer motor 86 continuing to the end of its programmedmachine cycle. However, if a malfunction occurs to cause the float 69 tostick in the upper position or to cause the switch 73 to stick in itsupper position, the machine will continue to operate until an attendantservices the machine.

If a malfunction should occur such as to cause the float '69 or switch73 to stick in their lower positions or if the condenser 22 fails toproduce condensate because of failure of blower 2-4 or pump 33, or ifthe water separator 47 or float chamber 68 should plug above the float69 with foreign articles precluding passage of solvent into chamber 68,the following conditions will occur:

At the beginning of the thirty-fourth timer interval, the first by passswitch 112 closes, and the second by pass switch 107 opens. At thebeginning of the thirty-fifth timer interval, cam 89 operates to openmain timer motor switch 106 and cam 88 operates to close the auxiliarytimer motor switch 113 which energizes the auxiliary timer motor 98.Because of the malfunction, a circuit is not made from line 81 throughswitch 73, switch 112, and through the timer motor 86 as is normally thecase. Therefore, the operation of the main timer motor 86 is interruptedand the drying interval is dependent on the thirty-minute operationinterval of the auxiliary timer motor 98 which is energized at thebeginning of the thirtyfifth timer interval of main timer motor 86.One-half minute before the end of the thirty-minute operation intervalof the auxiliary timer motor 98, cam 103 operates to close the auxiliarytimer motor interval switch 116 which provides voltage across timermotor 86 through switches 112 and 116. The main timer motor 86 thenoperates cam 89 to close the main timer motor switch 106. At the end ofthe thirty-minute time period of the auxiliary timer motor 98, cam 103operates to open the auxiliary timer motor interval switch 116 and cam88 operates to open the auxiliary timer motor switch 113, deenergizingthe auxiliary timer motor 98.

Under these conditions, the timer chart of FIGURE 2 is interrupted atthe thirty-fifth interval of the main timer motor 86 and actuallyexpanded in length by a thirty-minute interval which is the duration ofenergization of auxiliary timer motor 98.

After the lapsing of this thirty-minute interval and at the beginning ofthe thirty-seventh timer interval of main timer motor 86, cam 91operates to open the first by pass switch 112 and cam operates to closethe second by pass switch 107. As can be noted in FIGURE 3, the maintimer motor 86 is now energized through the second by pass switch 107and the lower contact of switch 73 as well as through main timer motorswitch 106. At the beginning of the fifty-fifth timer interval, cam 89operates to open main timer motor switch 106. However, the main timermotor 86 continues to be energized through the second by pass switch 107and the lower contact of switch 73.

At the beginning of the fifty-sixth timer interval, cam 89 operates toreclose main timer motor switch 106 and permit the timer motor 86 tocomplete the normal machine cycle.

While we have-illustrated a preferred embodiment of the invention in theaccompanying drawings, itshould be evident that various modificationscanbe'madeto the described apparatus without departing from the scope ofthe present invention.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as'follows:

1. In a dryingapparatus including dryingmeans for effecting the dryingofarticles placed insaid drying apparatus, dry controlcircuitry includingmeans, for energizing said drying'meansv during a drying operation,

first sequential control means inisaid circuitry for controlling saiddrying means throughout .a first fixed time interval,

switch means in saidcircuitry responsive to a'condition of dryness ofsaid articles and operable to termienate said drying operationsubsequentto said first fixed time interval, and

second sequential control means in said circuitry to override saidswitch means and limit the duration of said drying operation in case ofa-malfunction of said switch means.

2. In a drying apparatus-including drying means for effecting the dryingof articlesplacedinsaid' drying apparatus, dry control circuitryincluding means for energizing said drying means "duringa dryingoperation,

first sequential control -means in said' circuitry for controlling saiddrying means throughout 'a first fixed time interval,

switch means in said circuitry responsive to a condition'of dryness ofsaid articles for extending'said drying operation beyond said firstfixed time interval andthereafter terminating said drying operation,

a by-pass switch interconnected in said circuitry 'in parallel withsaidswitch means, and

second sequential control means in said circuitry for operatingsaidby-pass switch to limit the duration of said drying operation in theevent of a malfunction of said switch means. 3. In a drying apparatusincluding drying means for effecting the evaporation of'fluids fromarticles placed in said apparatus and further including condensing meansfor condensing vapors resulting from said evaporation during a dryingoperation, the combination comprising,

an electrical circuit for said apparatus including means 'forenergizingsaid drying means,

sequential control means in said circuit for controlling saild dryingmeans throughout afirstfixed time interva sensing means responsive tothe rate of flow of condensate generated bysaid condensing means,circuit means including a switch actuated by said sensing means betweenfirst and'secorid positionsfand means operative between said sequentialcontrol means and said switch providing checking intervals for extendingsaid drying operation beyondsaid first fixed time interval when saidswitch is in said first position and terminating said drying operationwhen said switch is in said second position.

4. In a drying apparatus including evaporation means for evaporatingfluids from articles placed in said app-aratus and condenser means forcondensing saidevaporated fluids during a programmed drying operation, adry control system comprising,

first sequential control means for controlling said evaporation meansand said condenser means and for carrying out said programmed dryingoperation, switch means being movable between first and second positionsdependent upon the flow of condensate from said condenser means, saidswitch means in said first position energizing said first sequentialcontrol means,

circuit means including said first sequential control means and saidswitch means in said first posit-ion,

by-pass circuit means in parallel with said switch means,

and

second sequential control means for energizing said by-pass circuitmeans to override said switch means to insure the energization of saidfirst sequential control means in the event of a malfunction of saidswitch means. 5. In a drying apparatus including evaporation means forevaporating fluids from articles placed in said apparatus and condensermeans for condensing said evaporated fluids during a programmed dryingoperation, a dry control system comprising,

first sequential control means for controlling said evaporation meansand said condenser means and for carrying out said programmed dryingoperation,

switch means being movable between first and second positions dependentupon the flow of condensate from said condenser means, said switch meansin said first position energizing said firstsequential control means,

circuit means including said first sequential control means and saidswitch means in said first position,

a bypass switch,

a by-pass circuit in parallel with said switch means and including saidby-pass switch, and second sequential control means for actuating saidbypass switch to energize said by-pass circuit to override said switchmeans and'insure the energization of said first sequential control meansin the event of a malfunction of said switch means.

6. In a drying apparatus including evaporation means for evaporatingfluids from articles placed in said apparatus and condenser means'forcondensing said evaporated fluids during a programmed drying operation,a dry control system comprising;

first sequential control means for controlling said evaporation meansand said condenser means and for carrying out said programmed dryingoperation, said first sequential control means providing a first fixedtime interval,

switch means having first and second positions as determined by the rateof flow of condensate from said condenser means, said switch means insaid first position energizing said first sequential control means aftersaid fixed time interval,

circuit means including said first sequential control means and saidswitch means in its second position, by-pass circuit means in parallelwith said switch means, and second sequential control means forenergizing said by-pass circuit means after said fixed time interval tooverride said switch means and insure energization of said firstsequential control means in the event of a malfunction.

7. In a drying apparatus having evaporation means for evaporating fluidsfrom articles placed in said apparatus and condensing means forcondensing said evaporated fiuids, a dry control system comprising:first sequential control means providing a first fixed time interval,

firstswitch means controlled by said first sequential control means,

second switch means responsive to the rate of fiow of condensategenerated by said condensing means and having a first position when saidcondensate .flow rate is below a predetermined value and asecondposition when said condensate flow rate is above saidpredetermined value, a first circuit including said first sequentialcontrol means and said second switch means, said first sequentialcontrol means being energized through said first switch means duringsaid first fixed time interval during which said second switch meansnormally moves from its first position to its second position to extendsaid drying operation beyond said fixed time interval,

and a second sequential control means operatively connected to saidfirst circuit to override said second switch means and to terminate thedrying operation during the extended time interval in the event of amalfunction of said second switch means.

8. In a drying apparatus including electrically energized heating means,electrically energized blower means cooperating with said heating meansto evaporate dry cleaning solvent from a load, and a timing mechanismarranged to program said apparatus through a timed sequence of drying,

a condenser receiving fluid evaporated from said load,

a water separator receiving the discharge from said condenser andarranged to separate water therefrom,

a dry control mechanism receiving condensed solvent from said Waterseparator,

dr-a-in means in said mechanism for constantly draining solventtherefrom,

a float in said mechanism,

a switch associated with said float and actuated thereby from a first toa second position when the level of solvent in said mechanism reaches apredetermined level,

and circuit means associated with said timing mechanism to providechecking intervals and being reresponsive to the position of said switchin said second position to continue energization of said blower meansand said heating means beyond their normal programmed energization uponmalfunctioning of said float in said dry control mechanism.

9. In a dry cleaning apparatus including an electrically energizedheater, a blower, and a solvent condenser including a condensate pumpfor circulating dry cleaning solvent, a control circuit comprising amain timer motor having timing cams thereon to energize said heater,blower, and condensate pump in timed sequence during an operating cycle,

a first cam operated switch actuated by said main timer motor toperiodicaly deenergize said main timer motor during an operating cycle,

a second cam operated switch arranged to apply energizing voltage acrosssaid main timer motor in one position of said switch during an intervalin which said first cam operated switch would otherwise deenergize saidmain timer motor,

float means responsive to the amount of condensate produced duringdrying,

a float operated switch in association with said float means and inelectrical series relation with said second cam operated switch,

a third cam operated switch actuated by said main timer motor andarranged to energize said main timer motor except for said interval inwhich said first cam operated switch would deenergize said main timermotor,

an auxiliary time motor,

a fourth cam operated switch actuated by said main timer motor toenergize said auxiliary timer motor during said interval in which saidfirst cam operated switch would otherwise deenergize said main timermotor, and

a fifth cam operated switch actuated by said auxiliary timer motor, andin parallel circuit relation to said float operated switch.

10. In a drying apparatus including drying means for effecting theevaporation of fluids from articles placed in said apparatus and furtherincluding condensing means for condensing vapors resulting from saidevaporation during a drying operation, the combination comprising,

an electrical circuit for said apparatus including means for energizingsaid drying means,

first sequential control means in said circuit for controlling saiddrying means throughout a first fixed time interval, and sensing meansresponsive to the rate of flow of condensate generated by saidcondensing means for extending said drying operation beyond said firstfixed time interval and thereafter terminating said drying operation, aby-pass switch interconnected in said circuit in parallel with saidsensing means, and second sequential control means in said circuit foroperating said by-pass switch to limit the dura tion of said dryingoperation.

References Cited by the Examiner UNITED STATES PATENTS 2,019,896 11/1935Edlich 34-45 2,166,294 7/1939 Hetzer 6818.2 2,911,810 11/1959 Lantz etal. 6820 X 3,002,287 10/1961 Smith 34-45 3,043,125 7/1962 Horecky 68123,085,415 4/1963 Gosnell 68--12 3,102,407 9/1963 Stilwell 6824 3,116,6251/1964 Stewart 6812 WALTER A. SCHEEL, Primary Examiner.

CHARLES A. WILLMUTH, Examiner.

1. IN A DRYING APPARATUS INCLUDING DRYING MEANS FOR EFFECTING THE DRYINGOF ARTICLES PLACED IN SAID DRYING APPARATUS, DRY CONTROL CIRCUITRYINCLUDING MEANS FOR ENERGIZING SAID DRYING MEANS DURING A DRYINGOPERATION, FIRST SEQUENTIAL CONTROL MEANS IN SAID CIRCUITRY FORCONTROLLING SAID DRYING MEANS THROUGHOUT A FIRST FIXED TIME INTERVAL,SWITCH MEANS IN SAID CIRCUITRY RESPONSIVE TO A CONDITION OF DRYNESS OFSAID ARTICLES AND OPERABLE TO TERMINATE SAID DRYING OPERATION SUBSEQUENTTO SAID FIRST FIXED TIME INTERVAL, AND SECOND SEQUENTIAL CONTROL MEANSIN SAID CIRCUITRY TO OVERRIDE SAID SWITCH MEANS AND LIMIT THE DURATIONOF SAID DRYING OPERATION IN CASE OF A MALFUNCTION OF SAID SWITCH MEANS.